Hurricane Sandy had Rare, 1-in-700-year Trajectory

A new study on the shape and trajectory of Hurricane Sandy reveals that the storm was a rare, once-in-centuries event marked by an unusual left-hand turn into the Atlantic Ocean before dealing a direct blow to the East Coast.

Timothy Hall, a co-author of the new statistical analysis and senior scientist at NASA's Goddard Institute for Space Studies, said Sandy's trajectory was so rare it only has a 0.0014 percent chance of happening every year.

"The particular shape of Sandy's trajectory is very peculiar, and that's very rare, on the order of once every 700 years," Hall told LiveScience.

Like many rare things, Hurricane Sandy was also expensive. Another recent study of the storm found that at $50 billion, it was the second costliest storm in U.S. history, behind Hurricane Katrina, which caused $128 billion in damage when adjusted to 2012 dollars. .

Sandy's near-perpendicular assault on the coast was a large factor in the severe flooding seen in New York, New Jersey and other affected states, Hall said. The National Hurricane Center attributed 72 deaths to Sandy.The storm's direct hit, combined with other factors including a full moon and the storm's ability to remain potent as it cycled along the Atlantic coast were a deadly and destructive combination.

But Hall also noted that just because Sandy is now tagged with the "700 year" label, it's no reason to let your guard down, even as the storm has passed.

"We don't want to lead with the misimpression that we don't have to worry, [that] it's going to be 700 years until we have another surge. That's not true," Hall told LiveScience.

Hall and is colleagues' research is published in the journal Geophysical Research Letters.